Fan-shot footage posted to social media shows Vedder, a well known Who fan, joining Roger Daltrey and Pete Townshend for a performance of "The Punk and the Godfather," a track from the band's rock opera Quadrophenia.
Vedder is in London for another Teenage Cancer Trust show. He's one of the many guests set to perform with Daltrey at Ovation, a Celebration of 24 Years of Gigs for TCT on March 24.